Broad social movement. We're aiming to focus on social media organizing at first, and then spread to local grassroots organizing later. There will be a lot of marketing and PR associated with it as well.

I don't know if social movements ever start from concerted efforts like this. For instance, EA started because one or two organizations and philosophers got a lot of interest from a few people. Other social movements start spontaneously when people are triggered into protest and action by major events. It seems good to have an identifiable 'core' to any kind of movement, like the idea I had - "a formal or semi-formal structure to aggregate and compare evidence from both sides." If you leverage swarm intelligence, prediction markets, argument mapping or more basic online mechanisms then you can start to make something impressive that stands on its own. Though such a system would be more difficult to make successful if you tried to make it relevant for the broad population rather than just EAs. It's just one example.

Yup, we're focusing on a core of people who are upset about lies and deceptions in the US election and the Brexit campaign, and aiming to provide them with means to address these deceptions in an effective manner. That's the goal!

I mean a core as in a fixed point of interest. E.g. a forum, a blog, a website, a college club, etc. Something to seed the initiative that can stand on its own without having thousands of active members. You can't gather interested people without having something valuable to attract them.